An intersection information acquisition unit acquires detection information by an object detection sensor including at least one of a vehicle detection sensor and a human detection sensor. A support processor performs driving support processing for outputting an alarm when the support processor determines that an own vehicle intends to cross the opposite lane and determines based on the acquired detection information that an object exists or the object is approaching in a direction in which the own vehicle travels to cross the opposite lane at the intersection. The support processor performs the driving support processing when the intersection information acquisition unit acquires detection information by the vehicle detection sensor. On the other hand, the support processor does not perform the driving support processing when the intersection information acquisition unit acquires detection information by the human detection sensor and does not acquire detection information by the vehicle detection sensor.